Cutting device



Sept. 10, 1935. J. c. OLSEN 2;013,894

CUTTING DEVICE Filed Aug. 2', 1954 2 Sheet s-Sheet 1 f9 'Irwenfor ohn6066870 Patented Sept. 10, 1935 CUTTING DEVICE John 0. Olsen, Chicago,111., assignor to Flexible Steel Lacing Company, Chicago, 111., acorporation of Illinois Application August 2, 1934, Serial No. 738,074

8 Claims.

This invention relates to improvements in cutting device, and moreparticularly a portable hand operated device for cutting sheet materialsuch as leather and canvas belting, rubber strips, linoleum and thelike.

One object of the invention is to provide a cutting device of thecharacter indicated which is efiicient in its cutting operation, iscomprised of relatively few parts of simple and inexpensive constructionto manufacture and easily assembled.

Another object of the invention is to provide a hand operated cuttingdevice wherein the material, while being cut, is firmly held againstshifting so as to insure a true cut and wherein the hold-down orclamping device is held by the operator in such manner that the greaterthe force exerted by one hand to effect the cutting of the material, themore pressure will naturally be exerted by the other hand of theoperator in holding the material in place.

A further object of the invention is to provide, in a cutting device ofthe character indicated, a clamping or hold-down device for the materialsuch that it will both readily and. automatically accommodate itself tomaterial of different thicknesses and, during the clamping or grippingaction, will automatically push or crowd the material firmly against theabutment which determines the alignment of the material so as to insurea true cut at exactly 90 to the gauged edge of the material.

A still further object of the invention is to combine with the hold-downor clamping device,

a guard for the knife so as to prevent possibility of injury to theoperator.

Other objects of the invention will more clearly appear from thedescription and claims hereinafter following.

In the drawings forming a part of this specification, Figure 1 is a topplan view of a cutting device embodying the improvements. Figure 2 is aside elevation of the structure shown in Figure 1, parts being brokenaway to more clearly illustrate the knife and the hold-down device beingalso shown in dotted position corresponding to that of the first instantof engagement with the material. Figure 3 is a vertical sectional view,upon an enlarged scale, corresponding to the section line 33 of Figure2. Figure 4 is an enlarged vertical sectional view corresponding to thesection line 4-4 of Figure 2. Figures 5 and 6 are detailed verticalsectional views corresponding to the section line 55 of Figure 1,illustrating two positions of the clamping device and associated parts.Figure 7 is a horizontal sectiona1 view, enlarged, of the knife andcorresponding substantially to the line 'l'l of Figure 2.

In said drawings, the cutting device comprises, broadly, a main frame A;a knife carrying slide 5 B; and a hold-down or clamping device C.

The main supporting frame A is of more or less triangular outline in topplan as shown in Figure l and is provided with a smooth, fiat,horizontal supporting surface H) for the piece of belt- 10 ing or othermaterial to be cut indicated in dotted lines at l I in Figure 1.

On its wider side, the frame A is provided with a rectilinear abutmentor gauging shoulder E2 of appreciable extent and against which the 15side edge of the material is to be cut is placed to determine itsposition, as will be evident. To lighten the structure and reduce theamount of metal required, the main frame A'is preferably cored orrecessed, as indicated at l3, l4, I5 and 20 H6. The frame is provided atthe several corners thereof with substantial preferably solid dependingsupporting legs I'l so that the same may be placed upon a table, benchor the like, when being used. 25

Adjacent its longest side, the supporting frame A is provided with atransversely extending noncircular and preferably rectangular channel orguiding recess l8 which is opened at the lefthand end of the device asviewed in Figures 1 and 30 2. Said channel or recess 18 is adapted to beclosed by a bottom removable plate l9 held in place by suitable machinescrews 2020, thus completing a rectangular guideway extendingsubstantially entirely across the supporting frame, for 35 the knifecarrying guide or operating member B which is of corresponding crosssection.

Said operating member B, of solid rectangular cross section, having aclose sliding fit within the guide channel, is preferably recessed atits inner 40 end, as indicated at 2|, on the side nearest the side edgeof the frame A, and within which recess or notch is secured the lowerend 22 of the knife, by means of set-screw 23. The operating member B isprovided with any suitable hand grip, such as 45 the knob 24, as shown,to adapt the same to be pushed or pulled, as will be apparent.

Communicating with the guide channel I8 and extending up through thesupporting surface of the frame A, is slot 25, through which is upwardly50 extended the cutting portion 26 of the knife so that the latter isadapted to engage and sever material held on the supporting frame. Atthe lefthand end of the slot 25, as viewed in Figure 2, the main frame Ais provided with an upstand- 55 ing rounded housing 26 suitablyinteriorly slotted as indicated at 2! and in which the cutting section26 of the knife is housed and protected when drawn to its extreme leftposition, as viewed in Figure 2.

Referring next to the clamping device C, the same, as shown, comprises amain clamping or hold-down arm 28 having at its outer free end, arounded hand hold-down 29 which, when the clamping device is inoperative position, extends over the knife housing 26, as clearly shownin Figure 2. The arm 28 is made of skeleton form and is widened out atits pivoted end or right-hand end as viewed in Figure 1 and, on itsunder side, is formed with fiat clamping surfaces 30' and. 3I whichconform substantially to the outlines of the arm except for thehold-down knob 29. As clear from Figure 3, that portion of the hold-downsurface, referenced 3 I, extends parallel to and closely adjacent theline of travel of the knife so as to positively insure the belt materialII or the like being firmly clamped immediately adjacent the slot in thesupporting surface on that side of the knife corresponding to the mainbody of the material being cut. The hold-down arm is also formed with aguard of inverted U section, as indicated at 32, along that edgeoverlying the path of movement of the knife so as to at all timesprotect the operator against the possibility of being cut by the knife.In this connection it will be noted that the outer side of the guardsection 32 does not come down. low enough to engage the material, sothat that portion II I of the material which is to be severed or trimmedoff, is not clamped but is free to be pushed out or away from the mainbody of the material during the cutting action and also that saidportlonl I I to be severed, is at all times supported on the outer sideof the knife slot so as to prevent it from bending down and hencedistorting the cut.

At its inner or wide end, the arm 28 is pivotally attached to a pin 33which in turn is carried by two spaced spring controlled plungers 34-44extending down through the bed of the main casting A within twointegrally formed sleeves or housings 35. Each of the plungers 34 isflanged or headed at its lower end as indicated at 36, which operates asa follower for a relatively heavy coil spring 3? encircling the plunger,the upper end of the spring being seated against the main frame A asclearly shown in Figures 4, 5 and 6. The frame A, above the guideshoulder I2, is formed with upstanding integral guides 38-38 for thepivot pin 33 and plungers 34 so as to insure a true straight up and downmovement of the pivoted end of the clamping arm. The springs 31 arenormally under compression so as to pull the inner pivoted end of theclamping arm down to its lowermost position but, as will be apparent,the arrangement is such as to permit the upward yielding of the innerpivoted end of the clamping arm to accommodate itself automatically todifferent thicknesses of the material I I being cut.

Referring now more particularly to Figures 5 and 6, it will be notedthat the pivotal axis of the of the pivot pin 33, that is, laterallyoffset with respect to a plane passing through said axis normal to boththe clamping and supporting surfaces. As clearly shown in Figure 5 wherethe clamping arm is initially engaging the piece of 5 material I I to becut, the point of initial engagement is at a greater distance from theabutment I2 than when it reaches its final position as shown in Figure6. During the change of position of the engaging rounded edge 39 fromthat shown in Figure 5 tothat shown in Figure 6, said rounded or cammingedge exerts a combined clamping and pushing action toward the right orgauging shoulder I2, thus automatically serving to push and crowd thematerial I I up solidly against the shoulder I2. As will be apparent,this not only insures that the material will be held down firmly againstthe supporting surface but also that it will be maintained firmlyagainst the abutment I2 so as to maintain the material true withreference to the path of movement of the knife during the cuttingaction.

The main frame A is also preferably provided with upwardly and outwardlyinclined lugs 4I'!4Il adjacent the pivots of the clamping arm so thatthe latter may be temporarily supported in inoperative position asindicated by the dotted lines I23 in Figure 2.

In cutting or trimming the material, the same is done by pushing theknife from left to right as viewed in Figure 2, that is by forcing theknife toward the abutment I2. Normally, the operator will employ hisright hand to push the knob 24 and his left hand on the hold-down knob29 of the clamping arm, and as greater pressure is 3' exerted in pushingthe knife through the material, the operator will naturally exert acorrespondingly greater downward pressure with his left hand in clampingthe material. At all times,

it will be noted the operator is fully protected 4 against injury fromthe knife.

Referring now more particularly to the knife, which is of specialconstruction, the active cutting part may be described as of generallythin fiat character. The side 26a, which is adjacent the main portion ofthe. material being cut, is disposed in a plane making a very slightangle with the line of motion of the knife, which line of motion isindicated at 5B. The other or outer side 26b of the knife is formed witha slightly curved surface extending at a relatively greater angle to theline of movement of the knife as clearly shown in Figure '7. At therear, both sides of the knife converge slightly, as shown. By incliningboth of the surfaces 25a and 26b from the line of rectilinear movementof the knife and diverging them as described and shown and thenconverging the rear portions of the surfaces, so as to make the thickestportion of the knife intermediate the front and rear edges thereof, theamount of force required to push the knife through a piece of materialof given thickness and characteristics is very substantially lessened ascompared with prior types of knives having a similar purpose. Experiencehas also demonstrated that a knife having the characteristics described,will make an absolutely straight out across the full width of thematerial without any tendency to draw or push the material trans- 7Oversely to the line of cut as the knife progresses therethrough, whichhas been a fault of prior constructions. Furthermore, by supporting thatportion of the material which is being severed on the outer side of theknife, the cut remains 75 a true vertical cut and without danger of thecut edge being beveled.

Although what is now considered the preferred embodiment of theinvention has herein been shown and described, the same is by way ofillustration and not by way of limitation, since it is evident thatvarious changes and modifications may be made without departing from thespirit 7 of the invention. All changes and modifications arecontemplated that come within the scope of the claims appended hereto.

What is claimed is:

1. In a cutter of the character described, a main frame having asupporting surface and a gauge abutment along one side thereof; a kniferectilinearly movably mounted on said frame toward and from saidabutment; and a clamping arm pivotally mounted on said frame, the axisof the pivotal mounting being disposed parallel to and outwardly of saidabutment, said clamping arm having a material-engaging edge alsoparallel to the abutment but on the inner side thereof, said edge beingadapted to initially engage the material and urge the latter toward theabutment as it is moved down to operative position.

2. In a cutter of the character described, a main frame having asupporting surface and provided with a gauge abutment along one sidethereof; a knife rectilinearly movably mounted on said frame at rightangles to said abutment; and a clamping arm having a yielding pivotalsupport on said main frame, the axis of the pivotalsupport extendingparallel to said abutment and located above said supporting surface.

3. In a cutter for relatively stiff materials such as leather, a mainframe having a fiat supporting surface and a gauging abutment along oneside thereof; a rectilinearly movable knife projecting above saidsurface and movable toward and from said abutment, and a combined clampand knife guard member pivotally attached at one of its ends to saidframe, said member having a clamping surface located adjacent one sideof the path of movement of the knife and a substantially inverted Usection extending upwardly therefrom and over the path of movement ofthe knife, the depending free edge of the outer side of said U sectionbeing disposed in a higher plane than said clamping surface whereby theportion of the material to be severed from the main body of thematerial, remains supported but unclamped during the cutting operation.

4. In a cutting device, a main frame having a supporting surface andprovided with a gauge abutment along one side thereof and a slotadjacent but inwardly of another edge thereof, said slot extending atright angles to the abutment; a knife slidably mounted on said frame andextending up through said slot; a knife housing at the outer end of saidslot and rigidly associated with said main frame; and a clamping arm,the latter having a clamping surface, a knife guard positioned over theslot and a pressure knob at its free end; and means for pivotallyattaching said arm to the frame.

5. In a cutter for belting and the like, the combination with a framehaving a flat supporting surface with a gauge abutment along one edgethereof and a slot extending at right angles to said abutment; anoperating bar slidably mounted on the frame below said slot; a knifecarried by said bar and extending upwardly 5 through the slot; a housingfixed with respect to said frame and disposed above said supportingsurface, for the knife at the end of the slot remote from the abutment;a combined knife guard and clamp member; and means pivotally attachingthe same to the frame, said means including a pivot pin extendingparallel to the abutment and spring controlled supports for said pin.

6. In a, material cutting device of the character described, thecombination with a main frame having a flat supporting surface for thematerial to be cut; of a gauging abutment along one side of saidsupporting surface; a cutting element; a clamping element for thematerial having a flat clamping face and a camming edge paralleling saidabutment; pressure applying means for said clamping element; anadjustable pivotal supporting and attaching means for said clampingelement to the main frame, the axis of the pivotal attaching means beingdisposed an appreciable distance above the plane of said clamping facewhen the clamping element is in operative engagement with the material,and said camming edge being laterally offset from said axis.

'7. In a cutter of the character described, a frame having a supportingsurface for the material to be cut; cutting means rectilinearly movablymounted and guided on said frame to sever material supported on saidsurface; an element having a clamping face arranged to engage thematerial; means for applying manual pressure to said element; andpivoted supporting means for said element and pressure means on the 40frame, the axis of said pivoted means being located an appreciabledistance above the plane of said clamping face when said element is inoperative clamping engagement with the material and the edge of saidclamping face which is nearest said pivotal supporting means, being alsolaterally offset to one side of a line passing through said axis normalto the clamping and supporting surfaces.

8. In a cutter of the character described, a 0 frame having a supportingsurface for the material to be cut; a knife rectilinearly movablymounted on said frame to sever material supported on said surface; aclamping element having a fiat clamping face; manual pressure apply--ing means for said clamping element; and yieldably mounted pivotalsupporting means for said element and pressure means, the axis of saidpivotal means being disposed an appreciable distance above the plane ofsaid element clamping 6O face when the latter is in operative clampingengagement with the material, the edge of said clamping face nearestsaid pivotal supporting means, being also laterally offset to one sideof a line passing through said axis normal to the clamping andsupporting surfaces.

JOHN C. OLSEN.

